METHOD OF PRODUCING POROUS CARBON MATERIAL FROM NATURAL GRAPHITE Russian patent published in 2010 - IPC C01B31/04 

FIELD: chemistry.

SUBSTANCE: invention relates to technology of carbon-graphite materials with high specific surface area and developed porosity, which can be used as sorbents and catalyst supports. Powdered natural cryptocrystalline graphite with particle size of 2-2.5 mm is treated with an oxidative mixture at boiling point for 10 hours and filtered off. The oxidative mixture used is melange which is a product of nitric acid production containing the following in wt %: H₂SO₄ -7.5-15; H₂O - 3.5-5; HNO₃ - the rest.Volume ratio of graphite to melange equals 1:6. The filtrate is centrifuged. Water is added to the obtained residue which is then centrifuged again, repeating these steps of washing with water until pH of the washing water equals 7. The washed material is dried and thermally treated at 800°C for 3 minutes. The obtained porous carbon material has specific surface area of 498 m²/g, pore volume of 0.270 cm³/g. Output of the desired product equals 20.3 wt %.

EFFECT: invention simplifies technology and lowers temperature for thermal treatment of oxidised graphite.

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